Dendrimers are three dimensional manmade molecules which, as illustrated in FIG. 1, have a three-dimensional, spherical or ball shape.
Dendrimer macromolecules are generally produced in one of two ways. See, for example, "Preparation of Polymers with Controlled Molecular Architecture. A New Convergent Approach to Dendritic Macromolecules," Hawker et al., J. Am Chem. Soc., 1990, 112, pp 7638-7747, which is incorporated herein by reference. The first of these methods is called the "divergent" approach. This method relates to the outward growth of the dendrimers from the center core in producing macromolecules. A second method for producing dendrimers is a convergent approach. In the convergent method, individual branches which make up the dendrimer are produced and these branches are then connected together to form the resulting dendrimer.
Dendrimers have generated a great deal of excitement largely due to their hollow, three-dimensional ball-like shape. It has been proposed to employ material "inside" the dendrimers which would allow the resulting material to be used in a variety of applications such as genetic therapy, drug delivery and even computer chips. For example, such "balls" can carry genetic materials into cells to repair birth defects. Alternatively, dendrimers can act as a delivery system for drugs.
It has further been proposed that dendrimers could be introduced onto a surface of a substrate. However, the art has not been able to successfully bond, and in particular, covalently bond, dendrimers onto the surface of substrates.
It is the belief of the inventors that the inability to effectively bond dendrimers to surfaces is a significant factor in preventing the practical use of dendrimers. For example, while as chemical sensors, has been mentioned, a practical way of employing dendrimers has not been found.